Zeljko Ivanek will guest-star on Revolution this season, TVGuide.com has learned exclusively.The Argo star will play Dr. Calvin Horn, whom creator Eric Kripke describes as "meticulous" and "a deeply curious scientist."Fall Preview: Get scoop on Revolution and more of your favorite returning showsIvanek, whose previous TV credits include Damages, Heroes and Big Love, will be one of a few new faces on Revolution this season, which will also feature Stephen Collins and Adam Beach.Are you excited to see Ivanek on Revolution? Whose side do you think Dr. Horn will be on?Revolution returns Wednesday, Sept. 25 at 8/7c on NBC.